Help with 4.6 stroker rebuild after failed cam gear

[Cheromaniac]

The Lunati Voodoo 63500 would be a good choice.

[kkchevy3]

what do you think would be better? lunati 63500 or 63501
http://www.lunatipower.com/ProductGroup ... 287&cid=48

[Cheromaniac]

I've simulated both on my engine dyno program and the 63500 makes more torque from idle to 4250rpm, so I think the choice is a no brainer.

[kkchevy3]

sounds like the 63500 for the win. what weight oil should i use for break in and what weight/brand after that. I live on long island (NYC)

[6TIME]

63500 Makes really good off idle and midrange torque. Make sure your compression is around the low 9's and you'll be very happy. Check the cam journals!

[gonridnu]

Has anyone tried just using a slightly longer pin for increased spring pressure?

Brilliant! Just Brilliant! Might even be able to get away with just a couple-few pounds more pressure since the natural action of the cam pushes it to the back of the engine.

[SilverXJ]

Might even be able to get away with just a couple-few pounds more pressure since the natural action of the cam pushes it to the back of the engine.

It should, but then why would it move out of the block?

[gonridnu]

The two most likely suspects that would cause cam walk is excessive distributor end play or a sloppy mesh between the dizzy gear and cam gear. Excessive oil pressure and high volume pumps compound the effect.

[dwg86]

Cams will walk forward. I have read that the way the lifters contact the lobes, and the way the lobes are ground, the cam shouldn't walk forward, but they do. Several engines I have built that didn't have a camshaft retaining plate had some indication of camshaft walk. The ones that come to my mind are all the amc V8's I have rebuilt,1-304, 2-360's and 1-401, all have had scuff marks where the cam sprocket retaing bolt has hit the timing chain cover. Most engines that didn't have a retaining plate have an aftermarket cam retaining solution.

I know some will want to argue that you only need a camshaft retaining plate, or pin, is if you are running a roller cam. But all the Fords I have built have had factory retaining plate. For example the Ford FE series engines(352,360,390,ect) have a retaining plate and never had a roller cam.

With all that being said, if you want to make a solid pin... remove the aft camshaft plug, you will need access to the rear of the cam. Install your camshaft, cam gear and bolt. Install your timing chain cover and gasket and tighten down. Pry the camshaft backward, so it's seated against the block. Install a dial indicator on the back of the camshaft. Now pry the cam forward until the cam bolt hits the timing chain cover. Take a reading from your dail indicator. This is how much the pin needs to protrude from the front of the cam bolt. I like a 0.000 to 0.005 clearance and I like to make the pin with a slight dome and polish the end. I like to get the pin to 0.000 and then polish the end. You will gain a little clearance when you polish the pin.

Don't worry about the pin wearing a hole in your timing cover. The spring and pin will put more pressure on the timing cover that a smooth polished pin that will be lubed with engine oil. And besides cams don't walk forward...right?

You will probably have to install and remove the timing cover several times as you get your measurments. Use a long grade 5, 1/4 bolt. Cut the bolt head off and the threads. These are cheap and you can get several just in case you mess up.

[Antifreeze2]

The spring and pin will put more pressure on the timing cover that a smooth polished pin that will be lubed with engine oil.

Thanks for the write-up, and sourcing my 12cwt crank. Don't know how that idea slipped my mind. A pin that's lubed and rolling in position only exerts the amount of force that is exerted upon it, where the spring is constantly trying to fight back.

[dwg86]

The spring and pin will put more pressure on the timing cover that a smooth polished pin that will be lubed with engine oil.

Thanks for the write-up, and sourcing my 12cwt crank. Don't know how that idea slipped my mind. A pin that's lubed and rolling in position only exerts the amount of force that is exerted upon it, where the spring is constantly trying to fight back.

You are welcome. It was nice to meet someone from jeepstrokers.

[kkchevy3]

so ordered the lunati cam. took the rod caps/mains w/e and they were down to copper. so guess the minimal detonation i had on the highway wasn't so minimal. will the new cam help with this at all. I already got rid of any sharp edges in the combustion chambers. I was going to go with the thicker head gasket but $$$$$$$. I was also already running a heat range cooler plug.

[wjtom]

can only say take everything from 505 with a grain of salt.everything i got from them was reboxed in blank packages.i worked in a speed shop for a bunch of years and have never seen a custom camshaft without some sort of identifing mark so it could be tracked.mine have nothing but the lobe separation on them.where it came from is hard to say plus it took close to 2 months to get.

[kkchevy3]

hmm so motors all in and running. idk i think i might have something wrong. first it pings under load. not all the time and not terrible but it pings. the idle is rough. like if you stood next to it you would know it has a cam in it by listening. and it just doesnt seem to have the power the old cam had. hits its wall at 4000. i also went with a colder plug. equivalent to a heat range 9 iifc. any ideas?

[SilverXJ]

That shouldn't be the case. The 68-232-4 and the 63500 aren't that different. The 63500 should give you a bit more power too. Did you install the cam straight up? Did you degree the cam in? Did you set the distributor correctly? Different plug manufactures use different heat range numbers, so what plugs are you using? Do you have an AFR gauge? When exactly does the pinging happen? What are you using for injectors and other fuel management?